肥胖
féipàng · HSK 7
fat
🐷 FEI (fertilizer) + PANG (expanding) = fattened up
肥 means fat or fertile (as in fertilizer that makes things grow large), and 胖 means plump. Together they double down: enriched and swollen, like soil so overfed everything bulges out.
肥 — flesh radical 月(肉) + 巴
Originally written with 肉 (flesh/meat) on the left and a phonetic-like component on the right, 肥 depicted abundant flesh on a body, hence 'fat' or 'plump'. Over time the 肉 radical was simplified to 月 in left-side position. The meaning extended from animal fatness to 'fertile' (as in rich soil) and 'fertilizer'.
胖 — flesh radical 月(肉) + 半 bàn (half)
A semantic-phonetic compound. The 月 element here is the 'flesh/meat' radical (肉), indicating something about the body, while 半 supplies the sound (bàn → pàng). The original sense referred to the half-side of a sacrificial animal's meat, later shifting to mean 'fat' or 'plump' in reference to a well-fleshed body.